1. Field of the Invention
The present invention relates to an image color extracting and recovering method, and a database generation and image searching method which are capable of automatically extracting an effect color of an image (which affects an original image color) pictured by a camera in accordance with an illumination condition and a color lens (or color filter) and a feature of the camera and processing the extracted effect color for thereby recovering an original image color.
2. Description of the Background Art
Generally, an image color of an object pictured using a certain camera (for example a digital camera, a video camera, etc.) may have an original color of an object and different image colors in accordance with a surrounding environment of the object and and a feature of the camera.
Namely, in the case that an object is pictured under an artificial illumination or pictured using a color filter mounted at the camera, an image color of an object pictured using the camera having different features according to a manufacturing company of the camera has a different color due to an effect with respect to the pictured image color. For example, if a white color clothes (for example, a wedding dress) under a yellow illumination is pictured using the camera, the white color clothes has a yellow-white color. Namely, the image color pictured using the camera has different image colors from those of the original image colors in accordance with the surrounding environment and the feature of the camera.
However, in the conventional image searching method, it is impossible to recover the original image color by correcting the image color which is different in accordance with the surrounding environment and the feature of the camera.
Accordingly, it is an object of the present invention to provide an image color recovering method for extracting an effect color which affects a pictured image color and correcting the extracted color irrespective of a surrounding environment of an object and a feature of a camera for thereby recovering an original color of the image.
It is another object of the present invention to provide an image color automatic extracting method which is capable of extracting an effect color which affects a pictured image color irrespective of a surrounding environment of an object and a feature of a camera.
It is still another object of the present invention to provide an image database formation method which is capable of extracting an effect color which affects a pictured image color irrespective of a surrounding environment of an object and a feature of a camera, correcting the extracted color for thereby storing the image as an original color image.
It is still another object of the present invention to provide an image searching method which is capable of comparing an image obtained by extracting an effect color which affects a pictured image color irrespective of a surrounding environment of an object and a feature of a camera correcting the extracted color and an image stored in an image database and searching a generated image.
To achieve the above object, there is provided an image color recovering method in a method for recovering an image color pictured based on a certain effect of an original color or other colors or an effect color in accordance with a feature of a camera and a surrounding environment of an object, which method includes the steps of comparing all pixels of a frame of the image and a first critical value, obtaining an average hue value Hue_Ave with respect to the hues of the pixels each having a chrominance smaller than the first critical value, computing a hue corresponding to the average hue value Hue_Ave, and determining the computed hue as an effect color, and compensating the image color affected by the effect color using the computed hue and adjusting the image color to an original color.
To achieve the above objects, there is provided an image color extracting method, in a method for extracting an effect color of an image affected by an effect color or any colors other than an original color owing to a feature of a camera and a surrounding environment of an object, which method includes the steps of: extracting a hue element of the pixels with respect to all pixels which form a frame of the image, generating a histogram with respect to the hue elements, and computing a maximum hue value Hue_Max based on the histogram; comparing the maximum hue value Hue_Max and a previously set first critical value, judging that there is an effect color which affects the image color when the maximum hue value Hue_Max is larger than a first critical value as a result of the comparison, dividing the image frame into grids, and generating the hue of each grid with respect to the grid having a chrominance smaller than the second critical value among the grids; and judging a hue corresponding to the average hue value with respect to the hues generated based on the grids as an effect color of the image when a difference hue value Hue_Diff between the average hue value Hue_Ave and the maximum hue value Hue_Max with respect to the hues generated from the grids is smaller than a third critical value.
In the image database formation method according to the present invention, a certain image is received, and the inputted image is processed to have an original color by an image color recovering method or an image color automatic extracting method according to the present invention.
In the present invention, the image searching method includes the steps of receiving a certain image and generating an image database for processing the inputted image to have an original color or storing the same based on a certain process, processing the currently inputted image by a certain process and generating an image having an original color, and comparing the current image processed to have an original color and an image stored in the image database.
Additional advantages, objects and features of the invention will become more apparent from the description which follows.